/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef PINYINIME_ANDPY_INCLUDE_LPICACHE_H__
#define PINYINIME_ANDPY_INCLUDE_LPICACHE_H__

#include <stdlib.h>
#include "./searchutility.h"
#include "./spellingtrie.h"

namespace ime_pinyin
{

	// Used to cache LmaPsbItem list for half spelling ids.
	class LpiCache
	{
	private:
		static LpiCache *instance_;
		static const int kMaxLpiCachePerId = 15;

		LmaPsbItem *lpi_cache_;
		uint16 *lpi_cache_len_;

	public:
		LpiCache();
		~LpiCache();

		static LpiCache &get_instance();

		// Test if the LPI list of the given splid  has been cached.
		// If splid is a full spelling id, it returns false, because we only cache
		// list for half ids.
		bool is_cached(uint16 splid);

		// Put LPI list to cahce. If the length of the list, lpi_num, is longer than
		// the cache buffer. the list will be truncated, and function returns the
		// maximum length of the cache buffer.
		// Note: splid must be a half id, and lpi_items must be not NULL. The
		// caller of this function should guarantee this.
		size_t put_cache(uint16 splid, LmaPsbItem lpi_items[], size_t lpi_num);

		// Get the cached list for the given half id.
		// Return the length of the cached buffer.
		// Note: splid must be a half id, and lpi_items must be not NULL. The
		// caller of this function should guarantee this.
		size_t get_cache(uint16 splid, LmaPsbItem lpi_items[], size_t lpi_max);
	};

}  // namespace

#endif  // PINYINIME_ANDPY_INCLUDE_LPICACHE_H__
